Two species of marine mammals have become extinct in modern times: the atlantic gray whale and the steller sea cow both joined the extinct species list back in the 1800's. more recently, scientists have declared the caribbean monk seal to be extinct. the best explanation for the extinction of these three species is a) deforestation. b) global warming. eliminate c) over-hunting by man. d) a drop in sea level

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.